Safety ventilator unit



Nov. 19, 1957 A. K. GAYLORD 2,813,477

I SAFETY VENTILATOR UNIT Filed March 16, l954 5 Sheets-Sheet l INVENTOR.A34 K 6.4 YL 0RD xii/M Nov. 19, 1957 A. K. GAYLORD 2,813,477

SAFETY VENTILATOR UNIT Filed March 16. 1954 V 5 Sheets-Sheet 2 INVENTOR.A: K GA YLORD 1957 A. K. GAYLORD 2,813,477

SAFETY VENTILATOR UNIT Filed March 16, 1954 5 Sheets-Sheet 3 INVENTOR.AsA K. GAYL0R0 Nov. 19, 1957 5 Sheets-Sheet 4 Filed March 16, 1954 G 8 77 5 .0 a J 8 3 5 1 I T 1 j w m m G I. F \J m JNVENTOR. A 5A K. GAYLORDNdv. 19, 1957 A. K. GAYLORD 2,813,477

SAFETY VENTILATOR UNIT Filed March 16, 1954 5 Sheets-Sheet 5 INVENTOR.

ASA K GA YLORD 2,8 13,477 Patented Nov. 19, 1957 ice SAFETY VENTILATORUNIT Asa K. Gaylord, Portland, Oreg. Application March 16, 1954, SerialNo. 416,469

23 Claims. (Cl. 98-115) This invention relates to an improved ventilatorfor installations subject to accumulations of inflammable deposits, suchas ventilators for removing grease bearing gases, vapors, fumes andsmoke from cooking ranges, grills, broilers, and other appliances usinghot oils and fats.

This application is a continuation-in-part of my prior co-pendingapplication, Serial No. 182,766, filed September 1, 1950, now abandoned.

Such ventilating systems constitute a serious fire hazard unless specialprecautions are taken to dispose of grease accumulations which resultfrom condensation of the grease bearing vapors from the various cookingprocesses. Without some form of grease extractor, the grease tends tocondense and accumulate in large quantities in the relatively coolductwork of the ventilating system, and mixed with the grease is usuallya quantity of soot from smoking cooking surfaces and meats. Thesedeposits are not only highly inflammable, but, when they build up tosome thickness in the ductwork, they contain enough fuel supply tocreate an intensely hot fire which will quickly ignite any nearby woodenstructure. The danger to the building is, of course, greatly increasedif the ventilating fans in the system continue to operate to supply thefire with oxygen under forced draft.

Attempts have heretofore been made to collect the grease in a receptacleor filter for its periodic disposal, and to prevent accumulations in themore inaccessible parts of the ductwork, but most prior devices for thispurpose are cleaned so infrequently in practice that they constitutealmost as great a hazard as if the grease had been allowed to accumulatein the duct itself. It must be recognized that there exists, not onlythe problem of keeping grease and smoke deposits out of the ventilatingduct, but also the problem of insuring that the collected grease will beremoved frequently and the problem of the prevention of a serious firein case the collected grease should ignite. It must be recognized,further, that, because of the highly inflammable nature of grease, therewill be occasional grease fires on the frying surface or in the broiler,even in the best regulated kitchens. For adequate fire protection, theventilating system must be designed, not only to reduce the likelihoodof fire as much as possible, but also to provide means for keepingoccasional and unavoidable small grease fires under control.

The general object of the present invention is, therefore, to provide animproved ventilating unit equipped with means to insure frequent removalof accumulated grease and further equipped with means to prevent a firefrom burning in the ductwork.

Further objects are to provide improved means for extracting the greasefrom the air stream and collecting it in a convenient receptacle, toprovide improved means to obstruct the flow of air through theventilating system and thus render it inoperative if the greasereceptacle is not cleaned regularly, to provide a novel form of damperfor the ventilating duct, and to provide thermal responsive means forclosing the damper in case of fire.

Another object is to provide an automatic fire stop damper mechanismwhich ,is required to function regularly in normal kitchen operation, inorder to insure its operability in case of emergency.

Another object is to provide a kitchen ventilator having steam cleaningand fire extinguishing nozzles.

Another object is to provide a ventilator unit of the type describedwhich is of simple construction, easy to clean, reliable in operation,and adapted to different kitchen requirements.

In general, the invention comprises the provision of a movable damperbaffle mounted in cooperative relation ship with a grease receptacle toassist in extracting grease and smoke particles from fumes and vaporsdrawn through the ventilating duct, and to obstruct the ventilatingpassage when the grease is not removed from the receptacle at regularintervals. By rendering the whole ventilating system ineffective by thepresence of an excessive amount of grease in the collecting receptacle,at least a certain minimum of cleanliness is insured and the receptaclewill not be allowed to fill until the volume of grease contains enoughfuel to constitute a serious fire hazard.

In case of fire, the damper baffle is tripped automatically by thermalresponsive mechanism which moves it to a position to close the duct andcut off all draft therethrough, the fan in the duct being stopped at thesame time. An important feature of the invention is that the dampermechanism may be designed so that it must be operated in order to obtainaccess to the grease receptacle to clean it out. Thus, the operatingmechanism of the protective device may be installed so that it must betested regularly and insured of being in good operating condition, andcannot stand idle for long periods of time to be rendered inoperative byrust or corrosion, as in the case of many protective devices whichfunction only in case of emergency. In the present system, the operatoris promptly apprised of any defect in the mechanism without making aspecial eifort to test it from time to time.

These and other objects and advantages will become apparent and theinvention will be better understood from the following description ofcertain preferred embodiments illustrated on the accompanying drawings.It is to be understood, however, that various changes may be made in theconstruction and arrangement of parts and that certain features may beused without others without departing from the spirit of the inventionas defined in the appended claims. It will be appreciated by personsskilled in the art that certain features of the invention may be usefulin ventilators other than kitchen ventilators where similar problemsarise.

In the drawings:

Figure 1 is a perspective view of installed in a kitchen;

Figure 2 is a cross sectional view taken on the line 2-2 of Figure 1;

Figure 3 is a cross sectional view taken on the line 3-3 of Figure 1;

Figure 4 is an elevation view taken on the line 44 of Figure 2;

Figure 5 is a fragmentary front elevation view of the central part ofthe structure shown in Figs. 1 and 4;

Figure 6 is an enlarged sectional view showing the damper baffie ofFigure 1 in closed position;

Figure 7 is a view similar to Figure 6 showing the damper baffle in openposition;

Figure 8 is an enlarged view of the apparatus in Figure 3 with one wallremoved from the damper bafile control mechanism housing to show thepositions of the parts therewithin when the damper baffle is in openposition; v

the present ventilator Figure 9 is a view similar to Figure 8 showingthe damper baffle in closed position;

Figure 10 is a schematic wiring diagram of the control system for theventilator;

Figure 11 is a diagram of the steam piping system;

Figure 12 is a cross sectional view showing an application of theprinciples of the invention to a ventilator installed in connection witha salamander or broiler;

Figure 13 is a view taken on the line 13-43 of Figure 12;

Figure 14 is a further modification in which the grease receptacle anddamper bame are installed in ductwork under the floor;

Figure 15 is an enlarged sectional view of the grease receptacle anddamper bafile of Figure 14; and

Figure 16 is a sectional view taken on the line 1616 of Figure 15.

Figure 1 embodiment Figures 1 to 11 illustrate a typical restaurantinstallation having a row of cooking units it projecting forward from aback wall 11. The ventilating duct 12 is ordinarily equipped with a fan13, shown in Figure 10, for drawing a strong current of air through theduct to withdraw from the kitchen the smoke, fumes, steam, vapors andcooking odors produced by the cooking units 10. The duct 12 has a lowerportion 14 with sloping walls which flare out to embrace the wholelength of the array of cooking units 10 as they are disposed along thewall 11. Mounted on the front wall Ma of the lower portion 14 is a shelf15 projecting out over the cooking units.

Air is drawn into the ventilating duct through a narrow throat 29between the bottom of shell 15 and a grease trough receptacle 21 mountedon the back wall 11. Trough 21 has a forward lip 22 spaced a shortdistance below the underside of shelf 14- to define the lower edge ofthroat 20. The upper edge of this throat is defined by the underside ofshelf 15 and the ends are defined by vertical end walls 23. One of theend walls 23 is omitted in Figure 1 to illustrate the internal structureof the ventilator. The walls 11 and 23, and the shelf 15, thereby form ahood to cause all the smoke, fumes and cooking vapors from the cookingunits 10 to be drawn through the narrow throat and expelled through theupper duct 12 into the outside atmosphere.

Air entering the throat 263 is required to pass around a damper baffle25 mounted on a shaft 26 supported on the frontwall 14a. When the damperbaffle 25 is in open position, as shown in Figure 2, its lower edge 25adepends downwardly substantially into the trough 21 approximately on thelevel of lip 22, although the edge 25a may be slightly above or slightlylower than lip 22 without departing from the principles of theinvention. A fixed bafile trough 27 projects forwardly into the airpassage of the lower portion of the duct 14 from the back wall 11immediately above the trough 2i. and on the approximate level of shaft26. The trough 21, damper baflie 25 and baifie trough 27 extend the fulllength of the array of cooking units 10 and shelf 15. Baffle troughs 28are mounted on removable panels 319 having handles 31. These panels areretained in place by spring catches 32, permitting each panel 30, withits integral trough 28, to be easily lifted out for cleaning purposes.

Steam pipes having nozzles 36 are mounted in the lower duct portion 14,as shown in Figure 2. The numeral 37 designates a number of temperatureresponsive switches which may be mounted in appropriate locations in theupper and lower duct portions 12 and 14. These switches are far enoughfrom the cooking units so that they are not affected by the heat of thevarious cooking operations but do respond to flame temperature in theductwork to close electrical circuits to certain control mechanismpresently to be described.

The numeral 4t) generally designates a damper operating mechanism which,in the present installation, is

mounted in the middle of the length of shelf 15 to open ate the bafiiedamper 25 by means of a lever arm 41. In the region of arm 41 the trough21 is shielded by a plate 42 on damper bafiie 25 which meets lip 22 andcloses a small portion of throat 2% when the damper is closed, as shownin Figures 3 and 5. The inner side of damper baflle 25 is equipped witha pair of gutters 43 which slope downwardly from opposite ends of thebaffle damper to a narrow gap 44. Products of condensation collected bythe gutters 43 drip from the ends thereof at the gap 44 immediatelybehind the shield plate 42 so that the draining material will dropfreely into the trough 21 and not be picked up and carried upward by therelatively high velocity air stream entering the throat 20.

Baffie trough 27 slopes downwardly from both ends toward a drainaperture 45 immediately behind shield 42, as shown in Figures 3 and 6.The drainage from aperture 45 thereby drips into a shielded portion oftrough 21 and is not picked up by the entering current of air. Aperture45 is placed in the forward side wall or lip 46 of the trough, ratherthan in the bottom, so that it will not pro vide a draft opening throughthe baffle trough 27 when the bafiie damper 25 is raised to its closedposition. Baflle trough 27 is of double walled construction whereby theinside of the trough slopes as described and the outside bottom of thetrough is horizontal to effect a substantially draft-tight seal with thelower edge 25a of the damper baffle when the latter is in closedposition.

The baflle troughs 28 are similarly constructed, having inner bottoms 47which slope toward the center of the ventilator as shown in Figure 4.The two troughs 28 drain into a short trough section 50 on front wall14a having a central drain aperture 51, as shown in Figure 3. The dripfrom this drain thereby falls through a relatively quiescent zoneimmediately behind and above the shield plate 42 where the air velocityis not sufiicient to pick up the drops and carry them along with the airstream. Upon removal of the panels 30 and troughs 23, there is affordedconvenient access to the interior of the lower portion of the ventilatorduct for wiping out the troughs 27 and 50 and the gutters 43. Thevertical dimensions are exaggerated in Figure 4 to show more clearly theslopes of gutters 43 and baflie trough bottoms 47.

When the damper bat-lie is closed, as shown in Figure 6, a narrow stripof metal 54 is engaged by the damper bafile, as shown, to close thedraft leak betweenshaft 26 and shelf 15. The strip 54 also forms a dripedge to prevent condensation liquids from running or creeping forwardalong the underside of shelf 15. When damper baffie 25 is in its openposition, as shown in Figure 7, a rear edge 55 abuts the underside ofshelf 15 to form a stop and also to close the draft leak between theshaft 26 and the shelf 15.

On smaller installations it is not necessary to provide two separatetroughs 28 and two removable panels 3t and in such case the dampermechanism 4t may be located at one end of the shelf 15 and shaft 26adjacent one of the end walls 23 with the troughs 27 and 28 and a singlegutter 43 all sloping toward a shielded region at one end of thestructure. Short trough section 50 would then be unnecessary.

Figure 8 also illustrates a grease level detector which may be providedas optional equipment, where desired. The numeral 56 designates aninsulator carrying an electrode 57 in the trough 21 just below the levelof its front lip 22. When condensation materials accumulate in thetrough 21 to a level L closely approaching the electrode 57, the changein capacitance between the trough and electrode produces a signal in thedetector apparatus 58 in Figure 10 which energizes relay solenoid 52 toclose switch 53 in parallel with the circuits of thermostats 37. Apreferred form of liquid level signal device is manufac'tured by FieldenInstrument Corporation of Philadelphia, Pennsylvania, under the tradename of Tector, type AJ-l.

I Figures 8 and 9 illustrate the construction and oper assign? lionofthe operating mechanism 40 for the damper bafile 25. t Lever41 projectsupwardly through slots 49 in the shelf and housing of the mechanism 40for connection with a plunger 60 having a manual operating knob 61. Apin 62 in the end of plunger 60 is engaged in slot 63 in the lever 41.Plunger 60 also carries a catch plate 64 which serves as a thrustabutment for compression spring 65. The other end of spring 65 abutsagainst a wall 66. Spring 65 is of sufficient strength to move plunger60 to the right and lift the damper bafile to closed position, as shownin Figure 9.

Damper bafile 25 is held open in its Figure 8 position by a latch bar 67which is pivotally mounted at 68 on a bracket on wall 66. Latch bar 67has .4. sloping nose 69, causing the latch bar to be cammed upwardly bythe catch plate 64 when the plunger is pushed in by the knob 61.

Latch bar 67 is raised to unlatched position by a magnetic plunger 71 insolenoid 70. A pin 72 in plunger 71 connects with a link 73 having aslot 74 receiving a pin 75 on the latch bar 67. Slot 74 provides a lostmotion connection between the latch bar and solenoid plunger to enablethe latter to acquire considerable upward velocity in free movementafter energization of solenoid coil 70 in order to add its own momentumto the pulling force of the solenoid to overcome the friction betweenthe latch bar and catch plate 64 in the unlatching movement. Solenoidplunger 71 also carries a striker plate 76. i

The numeral 80 designates a manual trip lever of L- shape which ispivotally mounted on a pin 81 and has an inner end 82 engaging theactuating button 83 of a normally open switch 84. It will be observed inFigure 10 that the closing of switch 84 energizes solenoid coil 70 tolift the magnetic plunger 71 and release the latch bar 67. In case thesolenoid 70 fails to operate, because of power failure or for some otherreason, a further movement of trip lever 80 will cause the arm 82 of thetrip lever to engage striker plate 76 and lift the solenoid plunger bymechanical action. A light pressure on trip lever 80 is suflicient toclose switch 84 but if the sole n-oid does not operate a firm pressureon the trip lever is necessary to lift the latch bar 67, therebyindicating to the operator that there is a fault in the electricalsystem.

A fan switch 85 having an actuating button 86 is mounted immediatelybehind the catch plate 64. In Figure 8, actuating button 86 is depressedby catch plate 64 to hold the switch 85 in closed circuit position, butwhen the catch plate is released by latch bar 67, as shown in Figure 9,the actuating button 86 is extended by an internal spring (not shown) toopen the switch and stop the fan 13.

Referring now to Figure 11, the steam pipes are supplied from a steamline 90 through a filter 91; Steam nozzles 36 may be operated at anytime by hand valve 92 for cleaning purposes, but this valve is normallyclosed. In case of fire in the ventilating duct, the nozzles 36 aresupplied with steam by operation of solenoid valve 93. This valve is ofconventional construction, having a valve member actuated by a magneticplunger which responds to the energization of solenoid coil 95 in Figure10.

Referring now to Figure 10, it will be observed that the switch 84in thedamper control mechanism of Figures 8 and 9 is one of a plurality ofmanual push button switches wherein the others are designated by thenumeral 96. The electrical system including these switches is energizedfrom supply wires 100, 101. Solenoids 70 and 95 are connected betweenthe wire 100 and a wire 102. Wire 102 may be connected with wire 101 toenergize the two solenoids by means of any one of a number of differentinstrumentalities connected in parallel. Manual switch 84 is operated bytrip lever 80 on the housing of control mechanism 40 in a convenientlyaccessible position to anyone working over the various cooking units.The switches 96 may be located on remote walls of the kitchen, and, ifdesired, one of them may be mounted outside the 6 kitchen. Eachthermostat switch 37 comprises a tubular metal shell containing abimetallic element which is normally in open circuit position andadapted. to close a circuit when subjected to an abnormal hightemperature. The switch contacts and bimetallic element are sealed intothe said metal shell so that these parts are not affected by grease andsmoke in the ventilator. The shell is equipped with a screw base forconvenient mounting projecting inwardly from the front duct wall 14a.The unit 58 is of conventional construction, the details of which areimmaterial to the present invention. This unit and its associated greaselevel detector contact 57, in Figure 8, are not essential to theinvention, but merely provide an additional means to compel cleaning ofthe grease trough receptacle 21 when an excessive amount of grease hasbeen allowed to accumulate. Ventilator fan 13 and unit 58 are energizedin a separate circuit controlled by the switch 85. As previouslyexplained, this switch is opened by the release of latch bar 67 fromcatch plate 64, either by manual trip lever or solenoid 70.

It will be apparent from Figure 10 that when the damper baffle 25 isclosed by operation of trip lever 80 or switches 84 or 96 it may beimmediately re-opened and latched open by merely pushing in knob 61.However, when it is closed by thermostats 37 or grease detector 58 itcannot be again latched open by knob 61 until the cause for its closingis removed. Main switch 103 may be opened to turn off the steam andpermit re-opening of the damper baffie and so this switch is preferablyremote from the kitchen and under the control of some person who isresponsible for keeping the fire extinguishing system in operativecondition.

Operation of Figure 1 embodiment When the kitchen is not operating, thecontrol mechanism 40 and damper bafile 25 are preferably left in thecondition shown in Figure 9, the damper bafile being in closed positionand the fan switch being open. Latch bar 67, of course, does not remainin its Figure 9 position but is dropped as soon as solenoid 70 isdeenergized, to be in position to engage latch plate 64 when the latteris again pushed in. It will be apparent that the closed down conditionof the system is readily effected by merely touching one of the pushbutton switches 84 or 96 or trip lever 80 to produce the same electricaland mechanical operation which is performed in case of emergency. Thus,the entire apparatus is normally tested daily to insure its operativecondition at all times, and the ventilating duct is thereby closed whilethe kitchen is unoccupied and is maintained closed by the action ofspring 65 without depending upon the electrical power supply. The springaction also insures the opening of switch 85 so that the fan 13 is notinadvertently left running.

In starting up in the morning, the knob 61 is pushed in, closing fanswitch 85 and moving the damper baffle 25 to its open position shown inFigure 8. The series of baffles 25, 27 and 28 provide a tortuous passagefor the air stream in the ventilating duct, requiring the air stream tomake rather sharp reverse bends, wiping the walls and the bafiles toextract products of condensation. in the air stream, as well as aconsiderable amount of greasy smoke, whenever such materials may bepresent. The condensed grease is thereby collected in the lower part ofthe ventilating duct where the temperatures are low enough to promotecondensation and yet high enough during operation of the cooking unitsto prevent congealing of the grease on such surfaces.

The grease and steam condensates, accordingly, drain down the duct wallsand are collected, but not accumulated, in one or the other of thebaflle troughs 27, 28. The trough shape of these baifies prevents suchdrainage from dripping off the edges in the high velocity air currentswhich would have a tendency to break up the drops and lift the resultingdroplets into the upper portion of the duct. Drainage openings 51 and 45are located in a portion of the duct which is shielded from the highvelocity air current by shield plate 42, whereby such drainage isassured of reaching the lowermost trough receptacle 21. Condensation onthe underside of baffle 50 may drain down the inner surface of panel 39,drip plate 54 and damper bame 25 to the gutters 43. The gutters 43collect such drainage and direct it to the central slot or gap 44 behindthe shield plate 42, where the condensate may drop freely into troughreceptacle 21 without interference from the high velocity air currententering the ventilating duct through the throat 20. Thus, there is nodrip from the lower edge 25:: of damper baffle 25 except in therelatively quiescent region where the baflle is shielded by the plate42.

The grease and steam condensates, accordingly, are suificientlyextracted in the lower portion of the ventilating duct and drain freelyinto the trough 21 leaving the upper and more inaccessible parts of theduct system relatively clean so that they do not require attention. Thebattles 2'7 and 28 are easily cleaned when necessary by removing thepanels 30, and the trough receptacle 21 is made entirely accessible byraising the damper baflie 25. The ease of keeping the system clean initself effects a material reduction in the potential fire hazard.

With reference to Figure 8 it will be observed that if material shouldbe allowed to accumulate in the trough 21 to the level L, the troughwould begin to function as a trap to impede the flow of air through theventilating duct and thus render the ventilating system substantiallyinoperative. Thus, the cook is compelled to clean out the trough 21 fromtime to time in order to maintain satisfactory ventilation in hiskitchen. This type of compulsion is found to be more effective thaninspection by the management or fire marshall in reducing the firehazard at its source. The grease level detector device 57, 58 willprovide an additional safeguard against excessive grease accumulation inthe trough receptacle 21, if the cook is oblivious to the diminishingventilation.

It will be appreciated that it is not necessary for the lower edge 25aof damper bathe 25' to project below the upper edge 22 of the troughbecause the ability of the ventilating system to remove cooking fumesfrom the kitchen is reduced to the point of ineffectiveness considerablybefore the liquid level actually reaches the lower edge of the damperbafl le. Battle 25 deflects the air stream down into the trough, causingthe air from throat 20 to be drawn transversely through the trough andso the precise height of the lower edge of the baffle is important onlyin regard to the degree of draft obstruction that is considerednecessary in a particular kitchen to compel the cook to clean thetrough. The important consideration is that the damper bafiie projectover the grease trough 21 in such relation to the trough that anexcessive depth of material in the trough will materially impede andobstruct the air flow under the lower edge of the baflle, compelling thecleaning of the trough. Preferably, also, the damper baflle has an openposition which interferes to some extent With the cleaning of the troughto compel periodic operation of the damper. The trough may be arranged,however, to be wiped out without raising the damper to closed position,if desired.

When a fire occurs, either on the range top or in the trough 21, it isprevented from spreading into the duct system by the automatic operationof one of the temperature responsive elements 37 or by the manualoperation of one of the switches 84, 96, if the fire is discoveredbefore the thermostatic devices have time to a steam nozzles 36, theventilating .ductand its-.bafilcs are easily cleaned by merely operatinga valve, and in case of fire, the action of the-steam will'smother thefire more quickly than merely shutting off its supply of oxygen at thebottom of the .duct.

Modifications ill ustrafed in Figures '12 to 6 Figures 12 and 13illustrate a ventilator embodying the principles of the invention foruse on a salamander or broiler 110, capable of producing greasy fumes orsmoke. The ventilating duct has an upperportion 1'1'1 equipped withthefan 1310f Figure 10. Thisportion of the duct includes aback wall 112and a front wall 113 which may carry one or more of the temperatureresponsive switch units37. The lower portion of the duct-comprisesinclined walls 114 and 1.15 and an inlet throat 120..

Connected with the wall 114 is a grease trough receptacle 121 having alip 122 defining one side of the inlet throat 120. A damper ib'aflle 125is mounted on a shaft .126 carried by the upperwallfor rotationbetweenthe open position shownrand aclosed position. -:In the open position ofthe damper battle, the l'oweredgeprojects substantially into the trough121 to deflect a current-of air entering the throat through thebottornof the trough. In closed position the-damper baffle engages :one.side of the trough to close the ventilating duct against the'current ofair. The damper baflle is operated by a lever 41a projecting upwardlythrough a slot 127 in the top wall 115 for actu. ation by the dampermechanism 40. In its open position a portion of the damper baffle closesthe space between shaft 126 and the top wall 115 and in its closedposition this space is closed by a resilient fin 128.

The entering air, after being deflected through trough 121 by damperbaflie 125, is again intercepted by another pair of grease extractingbafl ies 131) mounted on the bottom wall 114. These baffles are spacedfrom each other and from the side wallsof the duct to provide gaps 131for the drainage of grease and other condensation materials. Steamnozzles 36 are-mounted in the duct for cleaning and fire extinguishingpurposes. The top 'Wall 15 is preferably mounted on hinges 133 so thatit may be lifted'to provide access for wiping out the inner wallsurfaces, baflles and trough 121.

Figures 14 to 16 illustrate a downdraft ventilator having the greasetrap in the basement where it can readily be drained into a suitablereceptacle. A hood 200 interconnects upright side walls 201 over the topof the cooking unit 10 to direct the air into the vertical duct 202. Theair is drawn through grease trap 203 and duct 204 by suction fan .13.The previously described damper operating mechanism 40 is mounted on oneside of the trap 203 to move the crank arm 205 on shaft 206. Directlybeneath the end of vertical duct'2ti2 is a grease trough or receptacle221 removably secured in place by bolts and wing nuts 222 engaged withoutstanding ears 223 on the receptacle. Liquid condensate materials maybe drained from the receptacle by merely opening valve 224.

Damper baffle 225 is mounted on the shaft 206 and is provided with astop 226 to hold the baffle in the desired lower or open position. Uponresponse of the mechanism 40 to one of the instrumentalities shown inFigure 10, the mechanism 40 is actuated to rotate shaft 206 and swingthe damper baffle 225 up to its broken line position, shown at 225a, toengage and form an air seal with inwardly projecting flange plates 227.These flange plates form a small baffle at 228 to direct the downwardair flow against the damper baffle 225, whereby the air stream isrequired to make sharp reverse bends and wipe the baffles and confiningwall surfaces for the extraction of smoke and liquid condensatematerial, which substances will then drop into the receptacle 221.Damper baffle 22S deflects the air stream into and throughthe greasereceptacle. If the receptacle is not emptied frequently, the greaselevel will rise therein until it materially restricts'the air flow'around the lower edge aerat /t t) of damper baffle 225, therebyrendering the ventilating system ineflective and requiring the greasereceptacle to be emptied.

Steam nozzles 36 may be operated as in the previous embodiments forpurposes of cleaning or fire extinguishing.

From the foregoing illustrations it will be apparent to persons skilledin the art that the principles of the invention may be applied to stillother types of installations involving similar problems.

Having now described my invention and in what manner the same may beused, what I claim as new and desire to protect by Letters Patent is:

1. In a ventilating system for a cooking unit, a grease troughreceptacle, an air duct communicating with and extending upwardly fromsaid receptacle and arranged to drain liquid products of condensationinto said receptacle, means for moving a current of air through saidduct, a freely movable damper baflle mounted in said duct and having anopen position in which the lower edge of the bafile dependssubstantially into said receptacle to deflect said current of airthrough the receptacle, said damper baflle having a closed positionextending across said duct to close said duct, means to hold said damperbaifle normally in said open position, and a temperature responsiveelement in said duct operatively connected with said damper baffle toeflect the movement of the damper baflle to said closed position forclosing said duct in case of fire therein.

2. In a ventilating system for a cooking unit, a grease troughreceptacle, an air duct communicating with and extending upwardly fromsaid receptacle and arranged to drain liquid products of condensationinto said receptacle, a motor driven fan for moving a current of airthrough said duct, a freely movable damper baffle mounted in said ductand having a normally open position with a lower edge dependingsubstantially into said receptacle to deflect said air current throughthe receptacle, and means responsive to the temperature of the air insaid duct to deenergize the fan motor and move said damper bafile into aagainst said current of air.

3. In a ventilating system for a cookingunit, a grease troughreceptacle, an air duct having a pair of opposite 'walls extendingupwardly from said receptacle for con veying a current of air andarranged to drain liquid prodnets of condensation from said walls intosaid receptacle, said receptacle being connected with one of said walls,a movable damper baflle mounted on the other of said opposite walls todepend substantially into said receptacle .to deflect said current ofair through said receptacle, mechanical means to move said damper batfleto a position closing said duct to prevent the movement of air there-'through, and electrical means responsive to the temperature of the airin said duct to actuate said mechanical means, said mechanical meansafter actuation holding said damper bafile closed independently of saidelectrical means.

4. In a ventilating system for a cooking unit, a grease troughreceptacle, an air duct communicating with and extending upwardly fromsaid receptacle and arranged to drain liquid products of condensationinto the receptacle, means for moving a current of air through saidduct, a movable damper bafile mounted in said duct and having an openposition with the lower edge of the baffle depending substantially intosaid receptacle to deflect said current of air through the receptacle,spring operated means for moving said damper baflle to a positionextending across said duct to close said duct against said current ofair, a closed latch for restraining the operation of said springoperated means normally holding said damper baffle in said openposition, a solenoid for releasing said latch, and means responsive tothe air temperature in said duct for energizing said solenoid. b

5. In a ventilating system for a cooking unit, a grease position toclose said duct "trough receptacle, an air duct communicating with andextending upwardly from said receptacle and arranged to drainliquidproducts of condensation into said receptacle, a fan for moving acurrent of air through said duct, a baflle in said duct extendingpartially thereacross and having a lower edge depending substantiallyinto said receptacle to deflect said current of air through thereceptacle, spring operated means for closing said duct and stopping theoperation of said fan, a latch for restraining said spring operatedmeans, a solenoid for releasing said latch, means responsive to thetemperature of the air in said duct for energizing said solenoid, and amanual switch for energizing said solenoid.

6. In a ventilating system for a cooking unit, a grease troughreceptacle, an air duct communicating with and extendingupwardly fromsaid receptacle and arranged to drain liquid products of condensationinto said receptacle, means for moving a current of air through saidduct, a freely movable damper baffle mounted in said duct and having anopen position in which the lower edge of the baflle dependssubstantially into said receptacle to deflect said current of airthrough the receptacle, said damper baffle having a closed position toclose said duct, a temperature responsive element in said duct andoperatively connected with said damper baffle to effect. the movement ofsaid damper baifle to said closed position for closing said duct againstsaid current of air in case of fire therein, a removable wall panel insaid duct adjacent said temperature responsive element, and a bafile onsaid panel extending into said duct.

7. In a ventilating system for a cooking unit, a grease troughreceptacle, an air duct communicating with and extending upwardly fromsaid receptacle and arranged to drain liquid products of condensationinto said receptacle, means for moving a current of air through saidduct, said ducthaving a pair of opposite walls, a battle in said duct onone of said walls, a movable damper baffle on the other of said wallshaving an open position in which the lower edge of the baffle dependssubstantially into said recept acle to deflect said current of airthrough the receptacle and around both of said baflles in reverse bendsto extract solid and liquid particles from said air stream, said damperbafile having a closed position in engagement with said first baflle toclose said duct, and means operable while said ventilating system is inservice for moving said damper baflle from said open position to saidclosed position.

8. In a ventilating system for a cooking appliance, a grease trough, aninclined air duct having a bottom wall connected with said trough andsloping upwardly from the trough to drain liquid products ofcondensation on said bottom wall into the trough, said duct having a topwall comprising a hinged cover member, a damper balfie hingedly mountedon said cover member so that the lower edge of the damper bafifleextends substantially into said trough to deflect an air current in saidduct through said trough when the damper balfle is in open position,means urging said damper baflle to a closed position engaging saidtrough to close said-air duct, a latch holding said damper baflle insaid open position, and a thermostat in said duct for releasing saidlatch.

9. In a ventilating system for a cooking unit, a ventilating duct forconveying a current of air, said duct having a lower portion arranged todrain liquid products of condensation from more elevated portions, agrease trough receptacle connected with one side of said lower portion,a baflle mounted on an oppositeside of the duct above said receptacleand having a lower edge depending substantially into said receptacle,means for shielding a portion of said battle and receptacle from saidcurrent of air, a gutter on said bafile to collect drainage from saidopposite side of the duct, means for draining said gutter into saidshielded portion of said receptacle, a baflle projecting from said oneside of the duct above said receptacle, said last baffle comprising atrough to collect drain:

11 age from said one side of the duct, and means fordraining said troughinto said shielded portion of said receptacle.

10. In a ventilating system for a cooking unit, a ventilating duct forconveying a current of air,-said duct having a lower portionarranged todrain liquid products of condensation from more elevated portions, agrease trough receptacle connected with said lower portion and arrangedto accumulate said condensation, a damper baflle mounted above saidreceptacle for movement between open and closed positions, said damperbaffle having a lower edge depending substantially into said receptaclein open position and arranged to deflect said current of air throughsaid receptacle, said damper baffle in closed position extending acrossand closing said duct against said current of air, means for holdingsaid damper baflle in said open position, means urging said damper.baflle toward said closed position, temperature responsive means insaid duct operably connected with said holding means to release saiddamper baflle for movement from said open to said closed position, andmanual release means operably connected with said holding means. 7 11.In a ventilating system for a cooking unit, a ven- .tilating duct forconveying a current of air, said duct having a lower portion arranged todrain liquid products of condensation from more elevated portions, agrease trough receptacle connected with said lower portion and arrangedto accumulate said condensation, a damper baflie mounted above saidreceptacle for movement between open and closed limit positions, saiddamper bafile having a lower edge depending substantially into saidreceptacle in open position and arranged to deflect said current of airthrough said receptacle, said damper baflle in closed position extendingacross and closing said duct againstsaid current of air, means forholding said damper bafile in said open position, means urging saiddamper baflle toward said closed position, means for releasing saidholding means, temperature responsive means in said duct for actuatingsaid release means, and a liquid level detector in said receptacle foractuating said release means.

12. In a ventilating system for a cooking unit, a ventilating duct forconveying a current of air, said duct having a lower portion arranged todrain liquid products of condensation from more elevated portions, fluidnozzles in said duct, a grease trough receptacle connected with saidlower portion and arranged to accumulate said condensation, a damperbaflle mounted above said receptacle for movement between open andclosed positions, said damper baflle having a lower edge dependingsubstantially into said receptacle in open position and arranged todeflect said current of air through said receptacle, said damper bafflein closed position extending across and closing said duct against saidcurrent of air, means for holding said damper baffle in said openposition, means urging said damper baflle toward said closed position,and means for releasing said holding means and connecting said nozzleswith a supply of cleaning and fire extinguishing fluid.

13. In a ventilating system for a cooking unit, a ventilating duct forconveying a current of air, said duct having a lower portion arranged todrain liquid products of condensation from more elevated portions, fluidnozzles in said duct, a grease trough receptacle connected with saidlower portion and arranged to accumulate said condensation, a damperbaflle mounted above said receptacle for movement between open andclosed positions, said damper baflle having a lower edge dependingsubstantially into said receptacle in open position and arranged todeflect said current of air through said receptacle, said damper bafllein closed position extending across and closing said duct against saidcurrent of air, means for holdingsaid damper baflle-in said openposition, means urging said damper baffle towardsaid closed position,and temperature responsive means in said duct for releasing saiddamperbaffie to said closed position and connecting saidnozzles with a supplyof cleaning and fire extinguishing fluid.

14. In a ventilating system for a cooking unit, a ven- ,tilating ductfor conveying a current of air, said duct having a lower portionarranged to drain liquidproducts of condensation from more elevatedportions, a grease trough receptacle connected with said lower portionand arranged to accumulate said condensation, a damper baflle mounted.above said receptacle for movement between open and closed positions,said damper baflle having a lower edge depending substantially into saidreceptacle in open position and arranged to deflect said current of airthrough said receptacle, said damper baffle in closed position extending across and closing said duct against said current of air, springmeans urging said damper baflle to said closed position, a latch forholding said damper baffle in said open position, a solenoid forreleasing said latch, a circuit having a switch for energizing saidsolenoid, and a movable trip member mounted in cooperative relation withsaid switch and latch, said trip member having an initial movement toclose said switch and a further movement to engage and release saidlatch by mechanical action in case said solenoid fails to operate.

15. A safety kitchen ventilator comprising a duct for conveying acurrent of air, a plurality of grease extracting baflles in said duct,fluid cleaning and fire extinguishing nozzles in said duct, a thermostatin said duct, means for mounting one of said baffles for movement as adamper to close said duct against said current of. air, means holdingsaid movable baffle in open grease extracting position, means urgingsaid baflle toward closed position, and means controlled by saidthermostat for releasing said damper holding means and turning on asupply of fluid for said nozzles.

16. In a kitchen ventilator having a duct for conveying a current ofair, a grease extracting baffle in said duct, means mounting said bafliefor movement as a damper to a position closing said duct against saidcurrent of air, said baflle thereby having an open position and a closedposition, a member connected with said damper for moving said damperbetween said open and closed positions, a spring urging said membertoward closed damper position, a handle for moving said member to opendamper position, a latch for holding said member in open damperposition, a solenoid latch release mechanism, a switch for energizingsaid solenoid, and a movable manual trip member mounted in cooperativerelation with said switch and latch release mechanism, said trip memberhaving a first range of movement to close said switch for operating saidsolenoid to release said latch and a second range of movement tomechanically engage and actuate said latch release mechanism if saidsolenoid fails to operate.

17. In a kitchen ventilator, a vertical duct for conveying a current ofair, said duct having a pair of opposite vertical walls of a horizontalwidth greatly exceeding the spacing of the walls, an air inlet for saidduct extending substantially the width of said walls, baffles on saidopposite walls projecting into the duct at different elevations todeflect said current of air in a tortuous path for extractingcondensation products therefrom, each of said baflles being formed as atrough along the lower portion thereof extending substantially acrossthe width of said walls and arranged to collect liquid condensationproducts from said walls without dripping from said baflles through saidcurrent of air, each of said baflle troughs being sloped longitudinallythereof to drain condensation products there from at a predeterminedpoint and having a drain passage at said point, and means arranged tocatch the drain from said troughs.

18. A kitchen ventilator as defined in claim 17 wherein said baflletroughs slope longitudinally thereof from both side ends of said wallstoward the center of said walls to the condensation drain point, andsaid means to catchthe drain from the troughs comprising a singlereceptacle within the duct which is accessible for cleaning.

19. A ventilator as defined in claim 18 including means for shieldingeach of said ,drain points at the center of said walls from. saidcurrent of air whereby the drain from said troughs is further protectedagainst entrainment in said current of air.

20. A kitchen ventilator for removing grease-laden fumes and the likefrom cooking appliances in a kitchen comprising a ventilating duct,grease extracting baflles in said duct, means mounting one of saidbattles for movement as a damper to extend across and close said ductagainst the passage of air therethrough, means urging said damper baffietoward said closed position, a latch for holding said damper baffle inopen, grease extracting position, manual trip means outside of said ductfor releasing said latch, and a manual operator outside of said duct foropening said damper after said latch has been tripped.

21. A kitchen ventilator for removing grease-laden fumes and the likefrom cooking appliances in a kitchen comprising a ventilating duct,grease extracting baffles in said duct, fluid cleaning and fireextinguishing nozzles in said duct, a thermostat in said duct, a damperin said duct, means urging said damper toward a closed position closingsaid duct against the passage of air therethrough, means holding saiddamper in open position to permit passage of air through the duct, andmeans controlled by said thermostat for releasing said damper holdingmeans and turning on a supply of fluid for said nozzles.

22. In a kitchen ventilator having an air duct equipped with a damper,means urging said damper toward a closed position closing said ductagainst passage of air therethrough, a latch for holding said damper inopen position to permit passage of air through the duct, a solenoidrelease mechanism for said latch, a switch for energizing said solenoid,a movable manual trip member mounted in cooperative relation with saidswitch and latch release mechanism, said trip member having a firstrange of movement to close said switch and energize said solenoid forreleasing said latch and a further range of movement to mechanicallyengage and actuate said latch release mechanism if said solenoid failsto operate, and a manual operator for opening said damper.

23. A kitchen ventilator for removing greasedaden fumes and the likefrom cooking appliances in a kitchen comprising a ventilating duct, anexhaust fan in said duct driven by an electric motor for drawing acurrent of air through the duct, a grease trough incorporated in oneside of said duct, a grease extracting damper baflle pivotally mountedon an opposite side of said duct above said trough for movement betweenopen and closed positions, said damper baffle having a lower edgedepending substantially into said trough in open position and arrangedto deflect said current of air through the trough, said damper bathe inclosed position extending across and closing said duct against saidcurrent of air, means outside of said duct for opening and closing saiddamper baffle, and a switch actuated by movement of said damper baflleto energize said fan motor when the damper baffle is open and todeenergize said fan motor when the damper bafi le is closed.

References Cited in the file of this patent UNITED STATES PATENTS1,926,433 Cartmell Sept. 12, 1933 2,120,490 Drummond June 14, 19382,392,038 Gaylord Jan. 1, 1946 2,564,074 Musan-te Aug. 14, 19512,633,929 Farr Apr. 7, 1953 2,642,152 Dohrer June 16, 1953 FOREIGNPATENTS 697,328 Great Britain Sept. 23, 1953

